Im in the same boat as you, every little thing they so just annoys me i feel like such an outcast
I would think that's the whole reason you are upset, is because your living with them. But your time will come for you guys to live with eachother and he will irritate you too ;)
Just try to understand and be happy that your family is there for you and supporting you, some people aren't so lucky, and you won't want to move out later and feel sad/guilty for fighting with them all the time